1. Field of the Invention
The present invention relates to a tape cassette formed of a high transparency material and having tape ends thereof detected and a tape cassette of which the presence/absence is detected.
2. Description of the Related Art
Conventional Tape Cassette Regarding the Detection of a Tape End
The applicant of the present application proposed a tape cassette, as the conventional tape cassette of this type, disclosed by Japanese Utility Model Examined Application Publication No. 63-25595. FIG. 1 is a partially-cut perspective view of the tape cassette; FIG. 2 is a plan view of a lower case portion thereof; FIG. 3 is a perspective view of part S shown in FIG. 2; FIG. 4 is a perspective view of part E of FIG. 2; and FIG. 5 is a perspective view of part F of FIG. 2.
In FIGS. 1 and 2, a cassette case 1 consists of a lower case portion 2 and an upper case portion 3. The case portions 2 and 3 are assembled with their respective junction surfaces abutting on each other. A pair of tape containers 4, 4 are provided in this cassette case 1. Reels 5, 5 are rotatably arranged in the paired tape containers 4, 4, respectively. A tape (not shown) is wound around the paired reels 5, 5 and constituted so that the rotation of the reels 5, 5 allows the traveling of the tape. Also, a cover lock container 6 is provided on one front end portion of the cassette case 1 to be surrounded by wall portions 10d and 10e. A cover lock member 7 is rockably arranged in the cover lock container 6. The cover lock member 7 locks a cover (not shown) to a closed position. While a cassette is inserted into a recording and reproducing apparatus, the position of the cover is changed to an unlocked position.
A light emission element insertion hole 11 is provided at the central position of the lower case 2 to be surrounded by the wall portion 10a. While the tape cassette is being installed into the recording and reproducing apparatus, the light emission element 12 of the recording and reproducing apparatus is arranged in the light emission insertion hole 11. The recording and reproducing apparatus is provided with a pair of right and left light reception elements 13a and 13b. The paired light reception elements 13a and 13b are positioned outward of the right and left sides of the tape cassette, respectively while the tape cassette is being installed into the recording and reproducing apparatus. The tape cassette is also provided with sensor optical path holes 14a to 14e and 17a to 17d in wall portions 10a to 10e and 16a to 16d, respectively, which are positioned on straight lines L1 and L2 coupling the position of the light emission element 12 with the paired right and left light reception elements 13a and 13b, respectively.
To be specific, the light which advances from the light emission element 12 in right direction, is introduced into the tape container 4 by way of the sensor optical path hole 14a of the right semicylindrical wall portion 10a constituting the light emission element insertion hole 11 and the sensor optical path hole 14b of the wall portion 10b constituting tape container 4. FIG. 3 shows the sensor optical path holes 14a and 14b provided in the lower case portion 2. It is noted that sensor optical path holes (not shown) are also provided at the corresponding positions of the upper case 3. To be exact, the holes of the upper and lower cases 2 and 3 constitute the respective sensor optical path holes. After the light which is introduced into the tape container 4 passes through the tape traveling path on which the pulled-out tape travels, the light is introduced to the outside of the tape cassette by way of the sensor optical path hole 14c of the wall portion 10c constituting the tape container 4, the sensor optical path hole 14d of the wall portion 10d constituting the cover lock container 6 and the sensor optical path hole 14e of the wall portion 10e on the side surface of the cassette (which wall portion also serves as one constituting the cover lock container 6) and reaches the light reception element 13a. FIG. 4 shows the sensor optical path holes 14c to 14e provided in the lower case portion 2. It is noted that sensor optical path holes are also provided at the corresponding positions of the upper case portion 3 (except for the sensor optical path hole in the wall portion on the side surface of the cassette). To be exact, the holes of the upper and lower case portions 2 and 3 constitute the respective sensor optical path holes.
The light which advances from the light emission element 12 in left direction, is introduced into the tape container 4 by way of the sensor optical path hole 17a of the left semicylindrical wall portion 16a and the sensor optical path hole 17b of the wall portion 16b constituting the tape container 4. FIG. 3 shows the sensor optical path holes 17a and 17b provided in the lower case portion 2. It is noted that sensor optical holes (not shown) are also provided at the corresponding positions of the upper case 3. To be exact, the holes of the upper and lower case portions 2 and 3 constitute the respective sensor optical path holes. After the light which is introduced into the tape container 4 passes through a tape traveling path on which the pulled-out tape travels, the light is introduced to the outside of the tape cassette by way of the sensor optical path hole 17c of the wall portion 16c constituting the tape container 4, the sensor optical path hole 18a of a tape pad 18 which is a transparent member and the sensor optical path hole 17d of the wall portion 16d on the side surface of the cassette and reaches the light reception element 13b. FIG. 5 shows the sensor optical path holes 17c and 17d and the optical path hole 18a of a tape pad 18 provided in the lower case portion 2. It is noted that sensor optical path holes are also provided at the corresponding positions of the upper case portion 3, respectively (except for the optical path hole in the wall portion on the side surface of the cassette). To be exact, the holes of the upper and lower case portions 2 and 3 constitute the respective sensor optical path holes.
The wall portions 10c to 10e, 16a to 16d and the like which constitute the sensor optical path holes 14c to 14e and 15a to 15d on the optical path for the light from the light emission element 12 which comes out of the tape container 4, are colored with a low light reflectance color. In FIGS. 4 and 5, the colored portions of the lower case portion 2 are indicated by hatching. The corresponding portions of the upper case portion 3 are colored, as well.
With the above constitution, the light which advances from the light emission element 12 in right direction reaches the tape traveling path by way of the sensor optical path holes 14a and 14b. If a tape on the tape traveling path is a magnetic recording layer tape part, it does not transmit light and the light does not reach the light reception element 13a. If the tape on the tape traveling path is a high light transmittance leader tape part, it transmits light and the light reaches the light reception element 13a by way of the sensor optical path holes 14c to 14e. Further, the light which advances from the light emission element 12 in left direction reaches the tape traveling path by way of the sensor optical path holes 17a and 17b. If the tape on the tape traveling path is a magnetic recording layer tape part, it does not transmit light and the light does not reach the light reception element 13b. If the tape on the tape traveling path is a high light transmittance leader tape part, it transmits light and the light reaches the light reception element 13b by way of the sensor optical path holes 17c, 18a and 17d. Using the difference in the output voltages of the light reception elements 13a and 13b between a case where the tape on the tape traveling path is the magnetic recording layer tape part and a case where the tape is the leader tape part, it is detected whether the tape end is at a take-up side or a supply side.
Meanwhile, the light from the light emission element 12 contains not only components advancing toward the light reception elements 13a and 13b but also those which may be reflected by the flanges of the reels 5, the inner surface of the cassette case 1 and the like and which may reach the light reception elements 13a and 13b without passing the tape traveling path. Further, there are cases where external light is incident on the interior of the cassette case 1 from the windows or the like on the upper surface of the tape containers 4 of the tape cassette, the incident light is reflected by the flanges of the reels 5, the inner surface of the cassette case 1 and the like and reaches the light reception elements 13a and 13b without passing the tape traveling path.
Here, if the cassette case 1 itself is formed out of a low light reflectance material such as a black material, the quantity of light which reaches the light reception elements is very small. Due to this, the light reception elements 13a and 13b, less likely, malfunction. Conversely, if the cassette case 1 itself is desired to be formed out of a material having high light reflectance or high transparency, the quantity of the above-stated unnecessary light which reaches the light reception elements 13a and 13b becomes disadvantageously large.
In spite of the above fact, according to the conventional case, portions close to the light reception elements 13a and 13b are colored with a low light reflectance color, thereby making it possible to sufficiently attenuate the unnecessary light at those positions and to prevent the light reception elements 13a and 13b from malfunctioning. In other words, it is possible to produce a colorful tape cassette without the need to consider the color of the cassette case 1 and the like.
(Tape Cassette Regarding the Detection of the Presence/absence of the Tape Cassette)
The tape cassette is employed in various apparatuses beside the recording and reproducing apparatus. They involve, for example, an operational cassette changer for a duplicator. FIGS. 6 and 7 show an example of usage of the cassette changer. In FIGS. 6 and 7, a recording and reproducing apparatus 101 is a tape dubbing apparatus having two cassette drives and the like. A cassette changer 103 is coupled to one cassette insertion port of the recording and reproducing apparatus 101 through a coupling portion 102.
The cassette changer 103 has a cassette tray 105 slidably arranged in a changer main body 104. The cassette tray 105 is moved between a cassette reference position and the cassette delivery position of the recording and reproducing apparatus 101. A pair of cassette stoppers 107 are provided above the cassette tray 105 so as to hold a tape cassette 106 at a cassette set position. The paired cassette stoppers 107 are moved to be apart from each other (in arrow directions shown in FIG. 6B), whereby the tape cassette 106 drops into the cassette tray 105 while being guided by rollers 108.
A cassette press arm 110 sliding along a guide rail 109 is also provided at the changer main body 104. The cassette press arm 110 presses the side surface of the tape cassette 106, whereby the tape cassette 106 can be moved from the cassette reference position of the cassette tray 105 to a cassette eject position (cassette position) on a storage 111. The storage 111 is provided laterally of the cassette tray 105. The changer main body 104 is provided with cassette presence detection means 112 for detecting whether or not the tape cassette 106 is at the cassette ejection position on the storage.
The cassette presence detection means 112 has a light emission portion 112a and a light reception portion 112b receiving a detected light from the light emission portion 112a. The optical path CC of the detected light which has reached the light reception portion 112b from the light emission portion 112a is set to pass the cassette ejection position which is the cassette position.
Next, the function of the above-stated constitution will be described. As indicated by virtual lines shown in FIGS. 6A and 6B, the tape cassette 106 is set at the cassette position. In a start mode, the paired cassette stoppers 107 are moved to be away from each other and the tape cassette 106 drops into the cassette reference position on the cassette tray 105. Then, the cassette tray 105 moves to the cassette delivery position of the recording and reproducing apparatus 101 and the tape cassette 106 is installed into the recording and reproducing apparatus 101, thereby starting dubbing. When dubbing is finished, the tape cassette 106 is ejected from the recording and reproducing apparatus 101 and returned onto the cassette tray 105. Thereafter, the cassette tray 105 is moved to the cassette reference position and the tape cassette 106 at the cassette reference position is pressed by the cassette press arm 110 and ejected to the cassette ejection position (a state shown in FIGS. 7A and 7B).
If the next tape cassette 106 is put at the cassette set position, a start mode is selected and dubbing is executed through the same operation process stated above. If a user removes the tape cassette 106 from the cassette ejection position, detected light from the light emission portion 112a is not shielded by the tape cassette 106 and reaches the light reception portion 112b. Thus, the cassette presence detection means 112 detects that the tape cassette 106 is not at the cassette ejection position and then the tape cassette 106 is ejected to the cassette ejection position through the same operation process stated above. On the other hand, if the user does not remove the tape cassette 106 completed with dubbing from the cassette ejection position, detected light from the light emission portion 112a is shielded by the tape cassette 106 and does not reach the light reception portion 112b. Thus, the cassette presence detection means 112 detects that the tape cassette 106 is at the cassette ejection position, whereby even if there is a tape cassette 106 to be completed with dubbing, the tape cassette 106 is prohibited from being ejected to the cassette ejection position.
(Tape Cassette Regarding the Detection of a Tape End)
According to the above-stated conventional tape cassette, it is required to color the portions of the cassette case 1 near the light reception elements 13a and 13b. Due to this, a coloring step which is quite laborious is included in processing steps, with the result that production efficiency disadvantageously, greatly deteriorates and demand for mass production cannot be disadvantageously met.
Further, there is demand for forming the cassette case 1 itself out of a high transparency material. In that case, if the portions of the cassette case 1 are colored with a low light reflectance color, the color disadvantageously differs from an originally intended color.
(Tape Cassette Regarding the Detection of Presence/absence of the Tape Cassette)
If there is demand for forming the cassette case itself of the cassette 106 out of high transparency material and the tape cassette 106 is formed according to the demand, there is a possibility that a detection error occurs to the cassette presence detection means 112 described above. That is, even if the tape cassette 106 is at the cassette ejection position, the detected light from the light emission portion 112a transmits the cassette case and reaches the light reception portion 112b and the cassette presence detection means erroneously detects that the cassette is absent. If such an erroneous detection is made, the next tape cassette 106 is fed to the cassette ejection position even while the tape cassette 106 is at the cassette ejection position. As a result, the earlier tape cassette 106 drops from the storage 111 and damaged or, if the storage 111 has a drop preventive wall, a heavy load is applied to the cassette press arm 110 and the cassette changer 103 and the like are damaged.
It is, therefore, an object of the present invention to provide a tape cassette to solve the above-stated problems and capable of preventing malfunction in tape end detection irrespectively of the characteristics (color, transparency and reflectance) of a cassette case without extreme deterioration of production efficiency and capable of maintaining a color originally intended for the cassette case as much as possible if the cassette case itself is formed out of a high transparency material.
It is also an object of the present invention to provide a tape cassette to solve the above-stated problems and capable of preventing a cassette detection error even if a cassette case is formed out of a high transparency material.
To achieve the above object, there is provided a tape cassette having a pair of reels rotatably provided in a pair of tape containers, respectively, a tape being wound around the pair of reels and contained in the pair of tape containers, the tape consisting of a magnetic recording layer tape part and high light transmittance leader tape parts added to both ends of the tape, respectively, and having sensor optical path holes provided on wall portions, respectively, on a straight line coupling a position of a light emission element of a recording and reproducing apparatus with a position of a light reception element of the recording and reproducing apparatus so that light from the light emission element is introduced into the tape containers and light passing through tape running paths of the tape containers comes out of the tape containers and reaches the light reception element while the tape cassette is installed into the recording and reproducing apparatus, wherein a light shielding portion having a light shielding effect is provided around at least one of the sensor optical path hole right after the light from the light emission element comes out of one of the tape containers and next the sensor optical path hole.
According to the present invention, since a light shielding portion having a light shielding effect is provided around at least one of the sensor optical path hole right after the light from the light emission element comes out of one of the tape containers and next the sensor optical path hole, it suffices to provide light shielding portions around the two sensor optical path holes at most. Thus, it is possible to prevent malfunction in tape end detection irrespectively of the characteristics (color, transparency and reflectance) of the cassette case, capable of responding to the demand of mass production without greatly deteriorating production efficiency, and capable of maintaining a color originally intended for the cassette case as much as possible if the cassette case itself is formed out of a high transparency material.
In a preferred embodiment of the present invention, the light shielding portion is provided to have right and left widths of about not less than 1 mm from a center of an optical path coupling the position of the light emission element with the position of the light reception element by the straight line and to spread over an entire height of at least one of the wall portion right after the light from the light emission element comes out of one of the tape containers and the next wall portion.
According to this embodiment, it is possible to ensure preventing malfunction in tape end detection.
In a preferred embodiment of the present invention, the light shielding portion is formed out of a light shielding member bonded to at least one of the wall portion right after the light from the light emission element comes out of one of the tape containers and the next wall portion.
According to this embodiment, since it suffices to bond the light shielding members to two wall portions at most, it can be expected that production efficiency further enhances.
In a preferred embodiment of the present invention, the light shielding portion is constituted by forming the wall portion right after the light from the light emission element comes out of at least one of the tape containers and the next wall portion itself, out of a light shielding member to be colored with two colors when forming a cassette case.
According to this embodiment, since it suffices to form the cassette case to be colored with two colors, it can be expected that production efficiency further enhances.
In a preferred embodiment of the present invention, the light shielding portion is constituted by attaching a light shielding holder having the sensor optical path hole to at least one of the wall portion right after the light from the light emission element comes out of at least one of the tape containers and the next wall portion.
According to this embodiment, since it suffices to attach the light shielding holders to two wall portions at most, it can be expected that production efficiency further enhances.
Further, to achieve the above object, there is provided a tape cassette having a pair of reels rotatably provided in a pair of tape containers, respectively, a tape being wound around the pair of reels and contained in the pair of tape containers, the tape consisting of a magnetic recording layer tape part and high light transmittance leader tape parts added to both ends of the tape, respectively, and having sensor optical path holes provided on wall portions, respectively, on a straight line coupling a position of a light emission element of a recording and reproducing apparatus with a position of a light reception element of the recording and reproducing apparatus so that light from the light emission element is introduced into the tape containers, light passing through tape running paths of the tape containers comes out of the tape containers, passes through a cover lock container and reaches the light reception element while the tape cassette is installed into the recording and reproducing apparatus, wherein a cylindrical protrusion having a light shielding effect is provided at a cover lock member arranged in the cover lock container, and a sensor optical path hole arranged on the straight line coupling the position of the light emission element with the position of the light reception element is provided at the cylindrical protrusion while the cover lock member is at an unlock position.
According to the present invention, even if unnecessary light is incident on the sensor optical path hole of the cylindrical protrusion, it abuts on the inner surface of the sensor optical path hole and shielded by the absorption effect thereof. Thus, it is possible to prevent malfunction in tape end detection irrespectively of the characteristics (color, transparency and reflectance) of the cassette case, capable of responding to the demand of mass production without greatly deteriorating production efficiency, and capable of maintaining a color originally intended for the cassette case as much as possible if the cassette case itself is formed out of a high transparency material.
Moreover, to achieve the above object, there is provided a tape cassette having a pair of reels rotatably provided in a pair of tape containers, respectively, a tape wound around the pair of reels and contained in the pair of tape containers, the tape consisting of a magnetic recording layer tape part and high light transmittance leader tape parts added to both ends of the tape, respectively, and having sensor optical path holes provided on wall portions on a straight line coupling a position of a light emission element of a recording and reproducing apparatus with a position of a light reception element of the recording and reproducing apparatus so that light from the light emission element is introduced into the tape containers and light passing through tape running paths of the tape containers comes out of the tape containers and reaches the light reception element while the tape cassette is installed into the recording and reproducing apparatus, wherein at least one of an upper flange and a lower flange of each of the pair of reels is formed out of a reflection light attenuating material and a reflection light attenuating color.
According to the present invention, since unnecessary light abuts on the flange portions of the reels and shielded by the absorption effect thereof, it is possible to prevent malfunction in tape end detection irrespectively of the characteristics (color, transparency and reflectance) of the cassette case, capable of responding to the demand of mass production without greatly deteriorating production efficiency, and capable of maintaining a color originally intended for the cassette case as much as possible if the cassette case itself is formed out of a high transparency material.
Furthermore, to achieve the above object, there is provided a tape cassette provided with a light emission portion and a light reception portion for receiving detection light from the light emission part at an apparatus side, an optical path of the detection light reaching the light reception portion from the light emission portion set to pass a cassette position, and used with an apparatus for detecting presence and absence of the tape cassette depending on whether the detection light from the light emission portion reaches the light reception portion, wherein a cassette case is formed out of a high transparency material, and a prism portion for refracting or reflecting incident light in an emission direction in which the incident light does not reach the light reception portion is provided at a position of the cassette case on the optical path of the detection light.
According to the present invention, if the tape cassette is at the cassette position, the detection light from the light emission portion is refracted or totally reflected by the prism portion and does not reach the light reception portion. Thus, it is possible to prevent a cassette detection error in the tape cassette with a high transparency cassette case.
In a preferred embodiment of the present invention, the prism portion is formed integrally with the cassette case.
According to this embodiment, since the prism portion is formed simultaneously with the cassette case, the prism portion can be easily produced at low cost. In addition, compared with a case of providing a light shielding member at the position of the prism portion, this embodiment has advantages in that an assembly step is not necessary and problems such as attachment error, peeling and the like can be avoided.
In a preferred embodiment of the present invention, the prism portion is provided at a position of the cassette case on which the detection light emitted from the light emission portion is incident first.
According to this embodiment, since the distance from the prism portion to the light reception portion is long and it is possible to prevent the detection light from reaching the light reception portion even if a prism deviation angle is set small, the degree of freedom for prism design increases.
In addition, to achieve the above object, there is provided a tape cassette provided with a light emission portion for cassette presence and absence detection and a light reception portion for cassette presence and absence detection receiving detection light from the light emission part at an apparatus side, an optical path of the detection light reaching the light reception portion from the light emission portion set to pass a cassette position, and used with an apparatus for detecting presence and absence of the tape cassette depending on whether the detection light from the light emission portion reaches the light reception portion, and provided with a light emission portion for cassette end detection and a light reception portion for cassette end detection receiving detection light from the light emission portion at an apparatus side, and used with an apparatus for detecting presence and absence of a tape end depending on whether the detection light from the light emission portion reaches the light reception portion, wherein a light shielding member is provided on an optical path for tape end detection to block passage of unnecessary light deviated from the optical path; and the light shielding member is extended and an extended portion of the light shielding member is arranged on an optical path for cassette presence and absence detection.
According to the present invention, the prevention of malfunction in tape end detection is ensured for a high transparency cassette case, and further it is possible to prevent a cassette detection error without increasing the number of parts and deteriorating assemblage.
Further, to achieve the above object, there is provided a tape cassette used with an apparatus for detecting a tape terminal end depending on whether tape end detection light from a light emission portion reaches a light reception portion, wherein a prism portion for refracting or reflecting the tape end detection light from the light emission portion in an emission direction in which the light does not reach the light reception portion, is provided on a wall around an optical path notch through which the tape end detection light passes.
According to the present invention, since the tape end detection light from the light emission portion is refracted or totally reflected by the prism portion and does not reach the light reception portion, it is possible to prevent a cassette detection error in a tape cassette with a high transparency cassette case.
Also, to achieve the above object, there is provided a tape cassette provided with two light emission portions for cassette presence and absence detection and two light reception portions for cassette presence and absence detection receiving detection lights from the light emission portions at an apparatus side, first and second optical paths of first and second detection lights reaching the light reception portions from the light emission portions, respectively, set to pass a cassette position, and used with an apparatus for detecting presence and absence of the tape cassette depending on whether the first detection light and second detection light from the respective light emission portions reach the respective light reception portions; and provided with two light emission portions for tape end detection and two light reception portions for tape end detection receiving detection lights from the light emission portions at an apparatus side, third and fourth optical paths of third and fourth detection lights reaching the light reception portions from the light emission portions, respectively, set to pass the tape position, and used with an apparatus for detecting presence and absence of a tape end depending on whether the third detection light and fourth detection light from the light emission portions reach the respective light reception portions, wherein a cassette case is formed out of a high transparency material; prism portions for refracting or reflecting the first and second detection lights for cassette presence and absence detection in a direction in which the first detection light and second detection light do not reach the respective light reception portions, are provided at positions of the cassette case on first and second optical paths of the first and second lights for cassette presence and absence detection, respectively; and light shielding members are provided on third and fourth optical paths of third and fourth lights for tape end detection to block passage of unnecessary light deviated from the third and fourth optical paths, respectively.
According to the present invention, it is possible to ensure preventing malfunction in tape end detection for a high transparency cassette case and to prevent a tape cassette presence/absence detection error.
Moreover, to achieve the above object, there is provided a tape cassette provided with two light emission portions for cassette presence and absence detection and two light reception portions for cassette presence and absence detection receiving detection lights from the light emission portions at an apparatus side, first and second optical paths of first and second detection lights reaching the light reception portions from the light emission portions, respectively, set to pass a cassette position, and used with an apparatus for detecting presence and absence of the tape cassette depending on whether the first detection light and second detection light from the respective light emission portions reach the respective light reception portions; and provided with two light emission portions for tape end detection and two light reception portions for tape end detection receiving detection lights from the light emission portions at an apparatus side, third and fourth optical paths of third and fourth detection lights reaching the light reception portions from the light emission portions, respectively, set to pass the tape position, and used with an apparatus for detecting presence and absence of a tape end depending on whether the third detection light and fourth detection light from the light emission portions reach the respective light reception portions, wherein a cassette case is formed out of a high transparency material; a prism portion for refracting or reflecting the first detection light for cassette presence and absence detection in a direction in which the first detection light does not reach the light reception portion, is provided at a position of the cassette case on a first optical path of the first detection light; a first light shielding member is provided on a second optical path of the second detection light for cassette presence and absence detection, a second light shielding member is provided on a third optical path of the third detection light for tape end detection to block unnecessary light deviated from the third optical path; and a third light shielding member is provided on a fourth optical path of the fourth detection light for tape end detection to block unnecessary light deviated from the fourth optical path.
According to the present invention, it is possible to ensure preventing malfunction in tape end detection for a high transparency cassette case and to prevent a tape cassette presence/absence detection error.
In a preferred embodiment of the present invention, the first light shielding member is extended and an extended portion of the first light shielding member is set as the second light shielding member.
According to this embodiment, it is possible to reduce the number of parts and the number of assembly steps and to enhance production efficiency.
The nature, principle and utility of the invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.